Approximate a batter's Wins Above Replacement (WAR) from plate appearances, OBP, and SLG. This is a batting-only simplified formula that omits fielding, baserunning, and positional adjustments β it differs from official fWAR/bWAR.
β οΈ This result is a reference approximation only. Official WAR (FanGraphs' fWAR, Baseball-Reference's bWAR) also incorporates fielding runs, baserunning runs, positional adjustments, and park factors β this calculator only models batting contribution (an approximated wRAA) plus a replacement-level adjustment.
| WAR Range | Rating |
|---|---|
| 5.0 + | League Elite (5+) |
| 3.0 - 4.9 | All-Star Caliber (3-5) |
| 1.5 - 2.9 | Average Regular (1.5-3) |
| 0.0 - 1.4 | Replacement Level (0-1.5) |
| < 0.0 | Below Replacement (< 0) |
The overall WAR structure (batting + baserunning + fielding + positional adjustment + replacement runs, divided by a runs-per-win constant) follows FanGraphs' publicly documented "Understanding WAR" glossary. This calculator omits baserunning, fielding, and positional adjustments, using only an OBP/SLG-based approximate batting-runs estimate (an approximated wRAA) plus the replacement-level adjustment.
WAR (Wins Above Replacement) is a comprehensive metric expressing how many more wins a player is worth compared to a freely available, minor-league-caliber replacement player. It converts batting, baserunning, fielding, and positional value into runs, then divides by a runs-per-win constant (roughly 10 runs). A WAR of 1 means a player produced about one more win than a replacement-level player would have.
Official WAR requires park factors, fielding runs (UZR/DRS), baserunning runs, and positional difficulty adjustments β data that's impractical to compute individually. This calculator instead estimates batting contribution relative to league average (an approximated wRAA) using only OBP and SLG, adds a replacement-level adjustment scaled to plate appearances (roughly 20 runs per 600 PA), and divides by the runs-per-win constant. Fielding, baserunning, and positional adjustments are not included.
A simplified WAR of 5+ is typically read as league-elite, MVP-caliber; 3-5 as All-Star caliber; 1.5-3 as an average regular; 0-1.5 as replacement level; and below 0 as below replacement. Since this only reflects batting contribution, a player with excellent fielding or baserunning may have a higher official WAR than this approximation suggests.
This calculator does not account for fielding contribution, baserunning contribution, positional difficulty (e.g. shortstop vs. first base), or park factors. A strong defensive shortstop will likely show a higher real fWAR/bWAR than this simplified figure, while a poor defender at a demanding position may show a lower real WAR. Treat this tool as an educational way to quickly gauge batting contribution, not a substitute for official WAR.
FanGraphs (fWAR) and Baseball-Reference (bWAR) use different detailed calculation methods, so the same player can have different WAR values on each site. Both sites publish their full methodology, so if you need an accurate season WAR figure, refer to those official sources rather than this calculator. Use this tool as a learning aid to understand which components make up WAR.